USP Spectrum Expansion System
The following article was taken from Sinclair User - October 1983
ZX Spectrum Expansion. . . . Starts with one
card . . . . . Extend up to seven cards !
The price/computer power ratio of the Spectrum is tremendous but up to now it's lacked one
major thing compared with other Z80, 48k computers costing many times more -
U-Microcomputers have been the UK leaders in Apple Expansion cards, but with the Spectrum
we've had to provide the means to expansion (3 and 4 slot backplanes) as well as the
USP-ADAP - £6.90
A back to back adaptor needed when you buy your first card and later for the backplane.
USP-BBP3 - £35.65
A buffered 3 slot back plane, meaning it won't interfere with the Spectrums operation. It
will generally require an auxilary power supply either home built or the USP-Power supply
unit (available later). A side connector allows use of the ZX Printer and Microdrives.
USP-BPE4 - £25.30
Provides a further four slots after you have the USP-BBP3
USP-PROT - £18.30
Prototyping card - use to design and test your own circuits.
USP-232D - £34.50
Dual channel serial RS232 interface using the sophisticated and very powerful Z80DART
chip. Includes LPRINT and LLIST patches and a terminal emulator program. Baud rate
75-9600, full handshaking available.
USP-I/O - £29.90
General purpose parallel interface using versatile Z80PIO chip. Use to connect to parallel
printers, music synthesisers, plotters, D-to-A and A-to-D converters, relays, LED's. . .
It provides two 8 bit input or output ports with 4 handshaking lines.
USP-CENT - £3.45
A kit for use with the USP-I/O for centronics compatible printers.